A Puzzle

[Marie Hass]

Applying the lighting lessons I have learned through my mentoring sessions, encouragement from Terry (Loose Canon) and input from Mike Buckley, I have decided to post a cut glass vase I have been working on.

Granted, this is not a finished image. There is a lot wrong (reflection is on the inside not outside of glass, back of glass competes with the front of the glass, etc).

For this image, I used my 100W LED in my square soft box to light the background only. I used a white piece of foamboard at a 45 degree angle to add light in the background. I have elevated my vase so the table top and table edges do not show.

Any c&c or other lighting suggestions welcome. I am at a standstill.

Marie

[Shadowman]

Nice effort, most of your concerns can be addressed by positioning the camera or light sources, perhaps you should try tethered shooting so that you can view your setup on the actual screen you'll analyze and edit the image.

[Marie Hass]

John, I am shooting tethered.

Cut glass with facets is extremely difficult to shoot as it is difficult to light the front without creating refractions in the back.

I have gone around in circles with this one, biting my own tail. Do you have any pictures to share with me? I would appreciate it.

Marie

[Mike Buckley]

I like this, Marie. Very nice!

reflection is on the inside not outside of glass

I assume you're referring to the pair of dark lines parallel to the outside edges of the height of the vase. Try leaving the background and camera in place while moving the subject closer to the camera. Not knowing the exact details of your setup, making that change may or may not move those dark lines closer to the edges of the vase.

Keep in mind that some transparent glass (perhaps most of it) displays that issue at least to some extent. Even the example of this style of photography used in Light: Science and Magic displays the same issue though to less of an extent. Many of my photos display it, though to less of an extent. I don't find it objectionable so long as the outside edges of the glass are defined as in your photo.

back of glass competes with the front of the glass

That's always going to be an inherent issue when photographing the front and rear of glass that is cut all around. I think you've handled the issue very well here, perhaps as well as it can be handled.

[Shadowman]

John, I am shooting tethered.

Cut glass with facets is extremely difficult to shoot as it is difficult to light the front without creating refractions in the back.

I have gone around in circles with this one, biting my own tail. Do you have any pictures to share with me? I would appreciate it.

Marie

Marie,

It's actually been quite awhile since I tried photographing glass, although it's one of my favorite subjects it always vexes me as well. This image was shot with both flash and backlighting. One of hundreds of attempts.

[Loose Canon]

First, I think the shot looks good as is. The technique looks solid and I agree with Mike that you have handled it well. There’s not much more you could do along the lines of what you are talking about (almost) but I get that you might want to tweak it a bit Marie.

It’s hard to say not knowing where you have what placed Marie but I’d toss out a couple of ideas if I may? These would be based on in-camera and nothing done so much in post. I’ve never lit a piece similar to this so they are just things I might try based on what you are saying. They may or may not work.

As for lighting the front, I assume you would be talking about direct light in order to get the front of the piece brighter than the back? This might be tricky and, as you mentioned, blasting it with a direct light source isn’t a good idea. So things I might try would be to place a couple of reflectors in front of the piece just out of frame forming a “triangle”. Angling from the lens out at 45* or so on the tabletop. This might bounce some more light up front. Maybe along with this a piece of diffusion material cut as the same shape as the piece only slightly smaller. Then attached to the back of the piece to reduce the light coming through the piece. I don’t think much of this idea (it might make it worse) but only one way to know. I have done just the opposite of this shooting glass with liquid in it. But I used a reflector, rather than diffusion, to help give the liquid more glow. I’ve never tried it to cut light that way.

The shot shows the piece as it is, meaning the design cut is all the way around it and it is glass so we are going to see that through the glass when we hold the piece in our hands. We need to see that through the glass in a photo so I don’t really see the back competing with the front. That would not have occurred to me if you hadn’t mentioned it. But you could also try rotating the piece to see if there might be a composition (cut design placement) that you like better if you haven’t already.

The black reflections look to me to that they are on the outside of the glass, but more toward the back of the piece as opposed to the sides (@90*) which gives the illusion of them being inside the glass' empty space inside. I don't think this is a problem necessarily either because we automatically know there is empty space inside the piece. The dark reflections serve to help give a visual cue of the shape of the piece. Mike also mentioned the edges are not lost so that also reinforces the shape. If this is what you are referring to, and you want those reflections more to the sides?

The reflections are something dark in the studio. Most likely just the room itself outside the lighting area. More specifically the dark space that starts just outside of your white BG. If that space is not getting light it would cause the beautiful/defining black reflections. Again, hard tellin’, not seeing the set-up but it could easily be that you might try a little wider BG. That would probably bring the dark reflections more toward the sides of the piece and out around from the back and that is the first place I would look to make that happen.

If I were shooting this piece Marie, I would work with trying to get those black reflections to the side of the piece and let the rest stand. I kind of like the reflections where they are, but working with them to see how to put them where you want them would be well worth pursuing.

I would also say congratulations for not only producing a darned good image of this piece, using good solid techniques, but also (more importantly) your eye for detail.

Very well done.

[Loose Canon]

I know you didn’t ask (me anyway) Marie, but here is the only cut glass I have worked with to date.

I was gearing to shoot some blown glass and was looking more at lighting gradient BG’s and just needed a “stand-in”. Wanted to see what gradient BG’s I could come up with and the BG was lit purposely for the diagonal gradient you see. This piece was what I had on hand. It is a Waterford crystal decanter my Grandmother left me. It was shot almost two years ago. Lot of water under the bridge so to speak!

It was less shooting the glass and more looking at the BG and how it related to the piece. But the same basic technique you used for your glass piece. I was working under the requirements placed on me for the future blown glass shots. I didn’t process this shot the way I would have normally.

Notice the point speculars in the vertical cuts I would have cleaned up normally. Refractions breaking straight into the lens (Family of Angles). This piece has seemingly infinite angles to refract. But, in the bottom diamond cut area they worked in my favor giving some cool “sparkle”! Also some prismatic effect showing color spectrum which I would have de-saturated. I would have worked the dark reflections more in another scenario. To show “sparkle” you have to have nice, almost blown highlights to (sometimes very little) blacks and in between. Less blacks and in between than brights, but knowing how much is the art (and experimentation) of working with light.

Please feel free to give this shot a long hard look and a long hard critique Marie. Work your “eye for detail” and see what you see in it. I like the shot okay but I also know its problems. I would shoot it differently if I were shooting the glass now. It would be cool for you to see those problems and I am guessing you will.

I didn’t here, but sometimes a black card on either side or on top, out of frame, (for a shot like yours to give the top rim a black reflection) works well.

[Mike Buckley]

I would like to clear up one common misperception or at least inaccurate use of terminology already mentioned a couple of times in the thread: The dark lines that define the edges of transparent glass when photographed with a bright background are not reflections. So, we should not call them reflections. Those dark lines are actually the absence of light whereas a reflection is the presence of light.

The family of angles is an infinite number of angles occurring in three dimensions that, by definition, is the area in which direct reflections are occurring. A direct reflection, also called a specular reflection, by definition is a mirror image of the light source. Thus, a direct reflection is the presence of light.

Think of the opposite style of photographing transparent glass using a dark background. In that situation, the lines that define the edges of the transparent glass are bright. Those bright lines are direct reflections (mirror reflections of the light source). That explains why they are so bright.

There are multiple ways to accomplish the display of dark or bright lines that define the edges of transparent glass. Regardless of the methods used and how different they may seem to be at first blush, the undeniable physics of light are common to all of them. The particular detail of the physics of light that defines the edges of transparent glass has to do with the limits of the family of angles. As explained in Light: Science and Magic, "These limits tell us where the light must be if the edges of the glass are to be bright in the pictures or, conversely, where it must not be if the edges are to remain dark."

[Marie Hass]

Thanks, Mike,

I appreciate the clarification.

Marie

[Mike Buckley]

Now that you understand that, Marie, I should do some back-peddling to add further clarification.

The only thing that is necessary to define the edges of the transparent glass using a bright background is for those edges to be darker than the background; they can be grey in that situation, which is mostly the case in your photo. When the edges are in a range we call "dark" even though it is not pure black, a certain amount of light is being reflected.

The primary point comes back to what you mentioned a few days ago -- that you are learning how to use additive and subtractive light. When a presentation board is reflecting bright light, it is adding light to the scene. When a presentation board is reflecting dark grey or something we call dark, perhaps even black, it is subtracting light from the scene by virtue of the fact that it is absorbing more tones in the spectrum visible to the human eye than it is reflecting. So, in general, we call dark lines the absence of light even though we know only true black is the complete absence of light.

[Loose Canon]

Funny Mike!

A reflection, by more than one definition is (this is Oxford):

1. “The throwing back by a body or surface of light, heat, or sound without absorbing it”!

Glass indeed throws everything back as a body or surface of light. Including dark areas outside the body of light. The dark areas outside the lighting is indeed an absence of light, and that gets reflected off the glass and does not get absorbed by the reflective surface. It is important that this is understood as we look for the things that are causing problems on the set. Generally to solve the problem we have to find where these reflections (light or dark) are coming from.

Your so-called “misperception” is not as definitive, in my opinion, as you are implying and I'm guessing it is obvious where the comments went and what they meant.

But this is Marie’s shot of a piece of glass, which I think is pretty cool, she is killing it, and I'm digging that.

So shall we not discuss pedantics here on her thread?

[Mike Buckley]

Terry,

I was just trying to clear some things up as I understand them to help communicate about this stuff. Feel free to disagree with my thinking.

[Marie Hass]

Sorry it took me so long to respond to your posts, Mike.

I had to go out to OSU to the eye clinic, and getting there, being seen and getting home is an all day affair.. I have lost vision in a portion of my left eye. Luckily I am right eye dominant, so it has not affected my photography.

I will add the wealth of information you and Terry have provided to my knowledge bank. I think I need to re-arrange my tabletop so i can light from behind. The room is just so small it will be difficult to work around. Hmmmmm....a puzzle.

Marie

[Marie Hass]

Dear Terry,

Your cut glass is beautiful and you are so fortunate to have this rememberance piece!

What I see from your image, is that it parallels what I am doing in my own work. Choices must be made as to where to add and subtract light and when a piece, such as yours, contain a lot of different surfaces, it is hard to maintain consistent treatment.

Marie

[Mike Buckley]

I think I need to re-arrange my tabletop so i can light from behind. The room is just so small it will be difficult to work around.

It's not necessary to place the light source behind the subject, though that's the way I prefer to do it so far. That decision has nothing to do with the quality of the final image; instead, it has to do with my preferences for working with the required equipment in restricted circumstances.

The total working area that I use is only 6 x 9 feet and the shooting area that is a subset of that area is only 4 x 8 feet.